James Edward Raggi IV has posted a long but interesting explanation of how he plays D&D and its simulacra. There's some neat stuff here, a lot of which I agree with, and much of which mirrors my own practice. He's hard-core on following the dice, though:
The dice are God, carrying more authority than any player and carrying more authority than the guy running the game. Just picking up the dice is a sign that nobody at the table knows what's going to happen. No fudging. Ever.
If a "story" would be ruined by an "incorrect" roll of the dice, then we're playing wrong. The story is only apparent after the playing is done. It's not a goal in-game. Sort of. More on that later. But if I want something to happen, then I'll say it happens and not bother with a dice roll. I'm in charge only to the point that I pick up the dice. Then I'm not in charge anymore.